PYCNIDES OF CRUSTACEOUS LICHENS. 275 
Specimen 3. Var. subocellata, Ach. Easby Wood, Cleveland: Leight. Exs. No. 222- 
Spermogones are very abundant, small, brown, punctiform, scattered among the apothecia, 
and much more easily discoverable on the greenish thallus than in the two preceding 
specimens. The spermatia are here again linear, mostly straight, on short, simple 
sterigmata. 
Specimen 4. Var. arthonioidea, Scher. On bark of young oaks, Switzerland: Hepp 
Exs. No. 47. Spermogones and their contents have essentially the same characters as in 
Nos. 1, 2, and 3. They are very minute, brown, and punctiform, abundantly scattered 
among the apothecia. Their envelope is of deep-brown cellular tissue; cavity simple, 
spherical. The spermatia are linear, straight, or slightly curved, with rounded ends, on 
very short, linear, simple, inconspicuous sterigmata. 
Mudd (Br. Lich. p. 235) describes the spermatia of O. herpetica as “large in propor- 
tion to the size of the spermogones," and as “ gibbous;” while Nylander (Prodr. p. 161) 
characterizes them as straight, and about 57455 long. 
Species 3. O. ATRA, Pers. 
Specimen 1. On tree-barks, Yorkshire, Dr. Carrington. On one specimen, on a dif- 
ferent thallus, however, from the Opegrapha, and unassociated with its, or with other, 
apothecia, are pycnides, largish, black, papillæform, closely resembling the perithecia 
of some Verrucarie. The walls are of a greenish-brown-coloured tissue, made up of 
roundish cellules. The cavity is simple; the stylospores colourless, irregular as to form 
and size, frequently oblong or linear-oblong, but also occasionally oval or ellipsoid, simple 
or faintly 1-septate, sometimes with two polar nuclei, or with obscure indications of three 
septa. The basidia are very short, simple, and filiform. 
Specimen 2. Var. parallela, Leight. On tree-barks, Torquay, Devonshire: Leight. 
Exs. No. 245. Associated with Verrucaria gemmata. Here also there are pycnides, exter- 
nally very much resembling spermogones, occurring in a patch by themselves, not neces- 
sarily referable either to the Opegrapha or Verrucaria. ln this ease the stylospores are 
oblong, brown, and 1-septate. What may be considered either a second form of pyc- 
nide, or as spermogones, are externally the same, but contain irregularly-shaped, suboval 
corpuscles, borne on the apices of long, linear or filiform, slightly waved supports. The 
latter have the character more of basidia than of sterigmata, and their terminal cor- 
puscles of stylospores quite as much as of spermatia. 
Specimen 3. Var. parallela. On birch, Corramulzie Linn, Braemar, Aug. 1856: 
W. L. L. Associated with Verrucaria epidermidis. Spermogones are black and puncti- 
form, scattered among the apothecia, but especially external to the region occupied 
by the lirelle. Spermatia are rod-shaped, about 5555 long, on simple, short, linear 
sterigmata. 
Specimen 4. Var. hapalea, Ach. Ireland: in the Kew herb. Mistaken for O. macularis, 
Ach., which = Dichena rugosa, Fr., a fungus. Spermogones are very abundant outside 
the region of the lirellee, as very minute, black, punctiform, immersed, closely aggregated 
conceptacles. Sometimes, while the lirellæ occupy a smooth thallus, spermogones occur 
on patches of thallus that are much darker and more unequal in surface, or they grow 
